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Old January 25th, 2007, 07:53 PM
flippedrover's Avatar
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'94 D-90
Join Date: Dec 2003
Location: Ashburn,va
Posts: 2,984
Next time give me a call if you need a tow. I do live down the road from ya.

Can't you feel 'em circlin' (closin'in) honey?
Can't you feel 'em swimmin' around?
You got fins to the left, fins to the right,
and you're the only bait in town.
You got fins to the left, fins to the right,
and you're the only girl in town.

Jimmy Buffett

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Old January 25th, 2007, 08:35 PM
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Loic Fabro
95 D90 - 96 Disco -06 LR3
Join Date: Oct 2003
Location: Herndon, VA - USA
Posts: 1,600
Originally Posted by cgalpin
Sadly replacing the fuel pump has not solved it. The sad story goes something like this

1. Ponied up for replacing the complete pump assembly as I managed to twist one of the steel pipes coming out of the pump disconnecting the rusting connectors. Got a great deal from George at rovers down south though.
2. After installation, the telltale lighting issues of this problem where still there.
3. I futzed around a bit, not really changing anything, but running it for a while with the battery diconnected, the "problem" went away.
4. I started reconnecting everything bit by bit and eventually hooked up the battery again and still the problem was gone. Even stopped and started it a few times and it was running great.
5. Being foolish enough to think it might be solved I headed out for a test drive (in the snow) and went well until it broke down pulling into a gas station a mile from home. It died while braking, exactly the same problem as before, and the light problem was back.

At that time the fuel pump was not pumping! I got a tow home (btw, don't ever try get your wife to tow you home in the snow uphill..)

At home the light problem was still there, but the I could hear the pump. Right now it won't start, has the same "no fuel" symptoms as before (despite the pump working) so I'll replace the fuel filter once I get a hand pushing the POS into the garage. Too damn cold out there.

Sucks to be me.

What do you guys think:
- when you turn the ignition key in to start the truck, the fuel pump relay kicks in, instead of hearing a strong fuel pump noise, you hear a weak noise and the stop lights turn on.
- the lights turn off as soon as the fuel pump relay turns off.
- if you hit the brakes, the engine dies.

Here is my take: the fuel pump ground wire is not going to the ground instead, it is connected/touching the 12V input of the stop lights. Because the fuel pump and the lights are connected to each other, the fuel pump does not have the full 12V (i.e. two resistors => voltage split).
This also explain that if you hit the breaks, the fuel pump stops (because then it gets 12V on both sides).

Now.... How to we find where those wires are touching? Looks like there is a long piece of wire that goes through the chassis and no connector we can unplug..... Any way to troubleshoot this without cutting wires?

Originally Posted by Daddymow View Post
I have an ex MoD and an ex wife. The two no longer conflict with each other.
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it is not hoarding it is selective collecting
1995 D90 NAS
1996 Discovery NAS
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Old January 25th, 2007, 08:53 PM
cgalpin's Avatar
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Charles Galpin
'94 D90 ST, '63 SeriesIIA
Site Team
Join Date: Jan 2004
Location: South Riding, VA
Posts: 11,538
Originally Posted by flippedrover
Next time give me a call if you need a tow. I do live down the road from ya.
Yeah, didn't think it would be a hard thing Turns out Loic was also looking to go play in the snow (but I only found out later).

Loic, I agree that it seems something is putting 12V into the lighting circuit with the ignition on. Not sure it's the fuel pump wiring, but thats as good as any place to start. Ill double check all the points the wiring goes into the frame or through holes, and then start pulling the shielding off the wiring near the tank. I might have to drop the tank again to properly ID the wires, but I'll cut the wires and try run dedicated ground and/or power to the pump and see if anything changes.

When I had the tank out, I did find a section of the loom that had a wire that had "dead ended". But at the time I opened it up and made sure nothing was touching and it didn't change the problem. But Ill check it again.


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